/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package com.sun.org.apache.bcel.internal.util;

import com.sun.org.apache.bcel.internal.generic.*;
import com.sun.org.apache.bcel.internal.classfile.Utility;
import com.sun.org.apache.bcel.internal.Constants;
import java.io.PrintWriter;
import java.util.*;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache BCEL" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache BCEL", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

/**
 * Factory creates il.append() statements, and sets instruction targets.
 * A helper class for BCELifier.
 *
 * @see BCELifier
 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 */
class BCELFactory extends EmptyVisitor {
    private MethodGen _mg;
    private PrintWriter _out;
    private ConstantPoolGen _cp;

    BCELFactory(MethodGen mg, PrintWriter out) {
        _mg = mg;
        _cp = mg.getConstantPool();
        _out = out;
    }

    private HashMap branch_map = new HashMap(); // Map<Instruction, InstructionHandle>

    public void start() {
        if (!_mg.isAbstract() && !_mg.isNative()) {
            for (InstructionHandle ih = _mg.getInstructionList().getStart(); ih != null; ih = ih.getNext()) {
                Instruction i = ih.getInstruction();

                if (i instanceof BranchInstruction) {
                    branch_map.put(i, ih); // memorize container
                }

                if (ih.hasTargeters()) {
                    if (i instanceof BranchInstruction) {
                        _out.println("    InstructionHandle ih_" + ih.getPosition() + ";");
                    } else {
                        _out.print("    InstructionHandle ih_" + ih.getPosition() + " = ");
                    }
                } else {
                    _out.print("    ");
                }

                if (!visitInstruction(i))
                    i.accept(this);
            }

            updateBranchTargets();
            updateExceptionHandlers();
        }
    }

    private boolean visitInstruction(Instruction i) {
        short opcode = i.getOpcode();

        if ((InstructionConstants.INSTRUCTIONS[opcode] != null) && !(i instanceof ConstantPushInstruction) && !(i instanceof ReturnInstruction)) { // Handled below
            _out.println("il.append(InstructionConstants." + i.getName().toUpperCase() + ");");
            return true;
        }

        return false;
    }

    public void visitLocalVariableInstruction(LocalVariableInstruction i) {
        short opcode = i.getOpcode();
        Type type = i.getType(_cp);

        if (opcode == Constants.IINC) {
            _out.println("il.append(new IINC(" + i.getIndex() + ", " + ((IINC) i).getIncrement() + "));");
        } else {
            String kind = (opcode < Constants.ISTORE) ? "Load" : "Store";
            _out.println("il.append(_factory.create" + kind + "(" + BCELifier.printType(type) + ", " + i.getIndex() + "));");
        }
    }

    public void visitArrayInstruction(ArrayInstruction i) {
        short opcode = i.getOpcode();
        Type type = i.getType(_cp);
        String kind = (opcode < Constants.IASTORE) ? "Load" : "Store";

        _out.println("il.append(_factory.createArray" + kind + "(" + BCELifier.printType(type) + "));");
    }

    public void visitFieldInstruction(FieldInstruction i) {
        short opcode = i.getOpcode();

        String class_name = i.getClassName(_cp);
        String field_name = i.getFieldName(_cp);
        Type type = i.getFieldType(_cp);

        _out.println("il.append(_factory.createFieldAccess(\"" + class_name + "\", \"" + field_name + "\", " + BCELifier.printType(type) + ", " + "Constants." + Constants.OPCODE_NAMES[opcode].toUpperCase() + "));");
    }

    public void visitInvokeInstruction(InvokeInstruction i) {
        short opcode = i.getOpcode();
        String class_name = i.getClassName(_cp);
        String method_name = i.getMethodName(_cp);
        Type type = i.getReturnType(_cp);
        Type[] arg_types = i.getArgumentTypes(_cp);

        _out.println("il.append(_factory.createInvoke(\"" + class_name + "\", \"" + method_name + "\", " + BCELifier.printType(type) + ", " + BCELifier.printArgumentTypes(arg_types) + ", " + "Constants." + Constants.OPCODE_NAMES[opcode].toUpperCase() + "));");
    }

    public void visitAllocationInstruction(AllocationInstruction i) {
        Type type;

        if (i instanceof CPInstruction) {
            type = ((CPInstruction) i).getType(_cp);
        } else {
            type = ((NEWARRAY) i).getType();
        }

        short opcode = ((Instruction) i).getOpcode();
        int dim = 1;

        switch (opcode) {
            case Constants.NEW:
                _out.println("il.append(_factory.createNew(\"" + ((ObjectType) type).getClassName() + "\"));");
                break;

            case Constants.MULTIANEWARRAY:
                dim = ((MULTIANEWARRAY) i).getDimensions();

            case Constants.ANEWARRAY:
            case Constants.NEWARRAY:
                _out.println("il.append(_factory.createNewArray(" + BCELifier.printType(type) + ", (short) " + dim + "));");
                break;

            default:
                throw new RuntimeException("Oops: " + opcode);
        }
    }

    private void createConstant(Object value) {
        String embed = value.toString();

        if (value instanceof String)
            embed = '"' + Utility.convertString(value.toString()) + '"';
        else if (value instanceof Character)
            embed = "(char)0x" + Integer.toHexString(((Character) value).charValue());

        _out.println("il.append(new PUSH(_cp, " + embed + "));");
    }

    public void visitLDC(LDC i) {
        createConstant(i.getValue(_cp));
    }

    public void visitLDC2_W(LDC2_W i) {
        createConstant(i.getValue(_cp));
    }

    public void visitConstantPushInstruction(ConstantPushInstruction i) {
        createConstant(i.getValue());
    }

    public void visitINSTANCEOF(INSTANCEOF i) {
        Type type = i.getType(_cp);

        _out.println("il.append(new INSTANCEOF(_cp.addClass(" + BCELifier.printType(type) + ")));");
    }

    public void visitCHECKCAST(CHECKCAST i) {
        Type type = i.getType(_cp);

        _out.println("il.append(_factory.createCheckCast(" + BCELifier.printType(type) + "));");
    }

    public void visitReturnInstruction(ReturnInstruction i) {
        Type type = i.getType(_cp);

        _out.println("il.append(_factory.createReturn(" + BCELifier.printType(type) + "));");
    }

    // Memorize BranchInstructions that need an update
    private ArrayList branches = new ArrayList();

    public void visitBranchInstruction(BranchInstruction bi) {
        BranchHandle bh = (BranchHandle) branch_map.get(bi);
        int pos = bh.getPosition();
        String name = bi.getName() + "_" + pos;

        if (bi instanceof Select) {
            Select s = (Select) bi;
            branches.add(bi);

            StringBuffer args = new StringBuffer("new int[] { ");
            int[] matchs = s.getMatchs();

            for (int i = 0; i < matchs.length; i++) {
                args.append(matchs[i]);

                if (i < matchs.length - 1)
                    args.append(", ");
            }

            args.append(" }");

            _out.print("    Select " + name + " = new " + bi.getName().toUpperCase() + "(" + args + ", new InstructionHandle[] { ");

            for (int i = 0; i < matchs.length; i++) {
                _out.print("null");

                if (i < matchs.length - 1)
                    _out.print(", ");
            }

            _out.println(");");
        } else {
            int t_pos = bh.getTarget().getPosition();
            String target;

            if (pos > t_pos) {
                target = "ih_" + t_pos;
            } else {
                branches.add(bi);
                target = "null";
            }

            _out.println("    BranchInstruction " + name + " = _factory.createBranchInstruction(" + "Constants." + bi.getName().toUpperCase() + ", " + target + ");");
        }

        if (bh.hasTargeters())
            _out.println("    ih_" + pos + " = il.append(" + name + ");");
        else
            _out.println("    il.append(" + name + ");");
    }

    public void visitRET(RET i) {
        _out.println("il.append(new RET(" + i.getIndex() + ")));");
    }

    private void updateBranchTargets() {
        for (Iterator i = branches.iterator(); i.hasNext();) {
            BranchInstruction bi = (BranchInstruction) i.next();
            BranchHandle bh = (BranchHandle) branch_map.get(bi);
            int pos = bh.getPosition();
            String name = bi.getName() + "_" + pos;
            int t_pos = bh.getTarget().getPosition();

            _out.println("    " + name + ".setTarget(ih_" + t_pos + ");");

            if (bi instanceof Select) {
                InstructionHandle[] ihs = ((Select) bi).getTargets();

                for (int j = 0; j < ihs.length; j++) {
                    t_pos = ihs[j].getPosition();

                    _out.println("    " + name + ".setTarget(" + j + ", ih_" + t_pos + ");");
                }
            }
        }
    }

    private void updateExceptionHandlers() {
        CodeExceptionGen[] handlers = _mg.getExceptionHandlers();

        for (int i = 0; i < handlers.length; i++) {
            CodeExceptionGen h = handlers[i];
            String type = (h.getCatchType() == null) ? "null" : BCELifier.printType(h.getCatchType());

            _out.println("    method.addExceptionHandler(" + "ih_" + h.getStartPC().getPosition() + ", " + "ih_" + h.getEndPC().getPosition() + ", " + "ih_" + h.getHandlerPC().getPosition() + ", " + type + ");");
        }
    }
}
